Copper IUD PERIOD CHANGE?

I got my copper IUD in December, and like I was told beforehand, it made my periods much heavier and longer and my cramps much more painful. They said that should calm down after 3/6 months. Well here I am at month 6, and I've been spotting for about a week, not really even bleeding, just a thick, red/brown discharge sometimes accompanied by a little blood. Has anyone else experienced this? My period is usually right on time, so to have this be all there is for so many days has me worried.